<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<title>简单的html5 File测试 for pic2base64</title> 
<style> 
</style> 
<script> 
  window.onload = function(){ 
    var input = document.getElementById("demo_input"); 
    var result= document.getElementById("result"); 
    var img_area = document.getElementById("img_area"); 
    if ( typeof(FileReader) === 'undefined' ){
      result.innerHTML = "抱歉，你的浏览器不支持 FileReader，请使用现代浏览器操作！"; 
      input.setAttribute('disabled','disabled'); 
    }else{
      input.addEventListener('change',readFile,false);
    } 
  }
  function readFile(){
    var file = this.files[0]; 
    //这里我们判断下类型如果不是图片就返回 去掉就可以上传任意文件  
    if(!/image\/\w+/.test(file.type)){
      alert("请确保文件为图像类型"); 
      return false; 
    }
    var reader = new FileReader(); 
    reader.readAsDataURL(file); 
    console.log();
    reader.onload = function(e){ 
        result.innerHTML = this.result; 
        img_area.innerHTML = '<div class="sitetip">图片img标签展示：</div>![]('+this.result+')'; 
    }
  } 
</script> 
</head>
 
<body> 
  <form action="http://api.okayapi.com/?s=App.CDN.UploadImgByBase64&file_name=js_demo_test.jpg" method="post">
  <input type="file" value="sdgsdg" id="demo_input" /> 
  App_Key：<input type="text" value="" name="app_key">
  签名：<input type="text" value="" name="sign">
  <textarea name="file" id="result" rows=30 cols=300></textarea> 
  <p id="img_area"></p> 
  <input type="submit" value="提交">
</form>
</body> 
</html>